While fractures involving the tibia and fibula
are the most common lower extremity pediatric fractures, those involving
separation of the proximal tibial epiphysis are among the most uncommon
but have the highest rate of complication. Neer and Horwitz reported an
incidence of 0.8% of 2500 consecutive epiphyseal fractures. Therefore,
the general orthopaedist should encounter only a few of these injuries
during a lifetime of practice.

CASE HISTORY:

A 14 year old Hispanic male presented to an outside institution after
sustaining a hyperextension injury to his right knee during a soccer collision.
He had the immediate onset of pain and noted swelling of the knee during
the first hour after injury. He was unable to bear weight; flexion and
extension of the knee exacerbated the pain. He had no previous history
of injury to his right lower extremity. Outside records document the following
course.

PHYSICAL EXAMINATION:

Examination of the right lower extremity was remarkable for a knee effusion
with soft tissue swelling and diffuse tenderness at the proximal tibia.
The patient was unable to dorsiflex or evert his foot. Sensation along
the lateral calf and foot was diminished. The dorsalis pedis and tibialis
anterior pulses were palpable and there was good distal capillary refill.

RADIOGRAPHS:

AP and lateral views of the right lower extremity revealed a Salter
Harris III proximal tibial fracture with intraarticular extension into
the medial and lateral tibial plateaus. The epiphysis was anteriorly displaced
on the metaphysis.

CLINICAL COURSE:

The patient underwent closed reduction and application of a long leg
splint on the night of injury. Notes document a palpable dorsalis pedis
pulse after reduction. The patient presented again in the ER two days after
injury with complaints of weakness of toe movement and forefoot pain. The
splint was loosened.

He was seen in orthopaedic follow up two days later at which time he
was found to have diffuse swelling from the mid thigh distally, diminished
sensation of the lateral foot, cyanosis of the dorsum of the foot, fever
to 101.5, and poorly dopplerable pulses at the popliteal, posterior tibial,
and dorsalis pedis arteries. He underwent a venous duplex ultrasound of
the right lower extremity without findings of deep venous thrombosis.

He was taken to surgery where fasciotomies of the right leg were performed.
Exploration of the popliteal artery at the level of the fracture revealed
it to be contused and occluded. A reverse saphenous vein bypass graft was
placed and angiogram revealed flow into the posterior tibial artery. The
postoperative course was complicated by myoglobinuria, anterior tibial
and dorsalis pedis occlusion, muscle necrosis treated by sequential debridement,
and wound infection with methacillin resistant Staph. epidermidis.

Seventeen days after the original injury the forefoot was frankly gangrenous
and an open transmetatarsal amputation was performed .
Anterior and lateral compartment debridement of non-viable muscle left
the fibula exposed, and it was resected. The lateral tibia was drilled.
The patient underwent repeat debridements and whirlpool therapy with his
clinical course complicated by Pseudomonal infection of the wounds. He
underwent closure of his transmetatarsal amputation and split thickness
skin graft to his lateral wounds 88 days after injury.

The patient presented to A.I. DuPont 15 days later (103 days after injury)
with serosanguinous drainage from the upper portion of his lateral wound.
Irregular areas of sclerosis and lucency of the tibia on plain films and
CT
as well as irregular uptake on bone scan
suggested areas of necrotic bone and chronic osteomyelitis. A hand film
showed a bone age of 17 and scanogram documented a 2 cm leg length discrepancy.
A lateral cortical tibial sequestrum gradually demarcated. He was followed
for a year without lasting resolution of his drainage and underwent sequestrectomy
and open packing of the wound.

Now two years after injury, he remains on oral antibiotics; the lateral
wound has gradually closed and is without drainage. He has a 2 cm leg length
discrepancy and no angulatory deformity. Knee range of motion is 0 to 110
degrees and there is no ligamentous instability. He is an independent ambulator
in a boot with spacer and denies knee or leg pain.

ANATOMIC CONSIDERATIONS:

Proximal Epiphysis is relatively well protected from deforming forces

laterally buttressed by upper end of fibula

only the deep portion of the MCL inserts of the epiphysis; LCL inserts
on fibula

hook shaped tubercleoverhangs the metaphysis anteriorly

insertion of semimembranosus spans the physis in the posteromedial
corner

physis is extracapsular and has nearly circumferential reinforcement
of the perichondrium